1. Field of the Invention
The present invention relates to a nonaqueous electrolyte secondary cell, particularly to a lithium secondary cell capable of offering a high discharge energy density in the discharging of a high current.
2. Description of Related Art
A lithium metal, which exhibits the basest potential and the highest energy density per unit weight, has attracted attention as a negative active material in secondary cell systems directed toward an increase in energy density. On the other hand, a lithium-containing metal oxide capable of providing a high energy density, such as LiMn.sub.2 O.sub.4, particularly a compound having a spinel structure, has attracted attention as an active material in a positive electrode as opposed to the negative electrode. Such a lithium secondary cell is reported, for example, in Japanese Unexamined Patent Publication (Kokai) No. 2-139860.
As described in Japanese Unexamined Patent Publication (Kokai) No. 62-90863, carbon materials too are used as the negative active material in the above-described cells. The carbon materials can serve to prevent the occurrence of dendrites and provide cells that are safe and excellent in cycle life.
The above-described lithium secondary cells, however, could not yet exhibit satisfactory discharge and charge characteristics.
An object of the present invention is to solve the above-described problems and provide a secondary cell with a nonaqueous electrolyte that can offer a high discharge energy density in the discharging of a high current.